1. Field of the Invention
The electrostatic precipitator, also referred to as a two-stage electrostatic precipitator, or simply as an electronic air cleaner, is useful in cleaning air, particularly in industrial applications, prior to returning it to the atmosphere. The unit has particular application when removing very fine, powder-like particles in the neighborhood of 1 micron and below, although the unit will handle virtually any airborne particles existing in the air stream being treated. It is designed to provide a clean atmosphere while at the same time, in some instances, effecting recovery of materials which may be recycled.
Although the electronic air cleaner of this invention is capable of removing not only dry particulates or contaminants from an air stream, but also of removing liquid particles therefrom, such as when "smoke" is removed from the treated air, the means and method for the cleaning and self-cleaning of such electronic air cleaner are particularly suited for use when only dry contaminants are being precipitated from the air stream being treated. (A significant percentage of "smoke" is often a liquid, but even under those conditions the cleaning means and method of this invention may produce some improvement in dislodging precipitated contaminants from the plates and/or wires on which they collect.)
2. Description of the Prior Art
Electrostatic precipitators as such are known in the art. An ionizer is utilized to produce an electrostatic field so as to charge the particles exposed to it. These charged particles are then passed through a collecting cell comprised of charged and grounded plates such as to pick-up the charged particles or contaminants. Some of the known United States Patents relating to such precipitators and the like are U.S. Pat. Nos. 1,697,316 -- Horny; 2,347,709 -- Penny; 2,470,356 -- MacKenzie; 2,476,248 -- MacKenzie; 2,542,262 -- Richardson; and 2,642,952 -- Landgraf.
There is also some known United States art pertaining more particularly to the removal of precipitated material from the collecting plates. Such art includes the following U.S. Pat. Nos.: Ekstrom -- 2,667,941; Palmer -- 2,490,979; Gately -- 3,605,9155 and Labbe -- 1,758,404.
It is known that there are a number of other United States Patents relating to electronic air cleaners but it is believed that those mentioned above are the most pertinent to the instant invention. No assertion is made, however, that such patents are indeed representative of the best art in this area, that is, the art closest to the invention herein shown, described and claimed.